1. Field of the Invention
The present invention relates to components which are composed of at least one continuous fiber reinforced thermoplastic polyamide component and one rubber component, which are bonded together without the use of coupling agents or adhesives.
2. Description of the Background
A single material cannot always provide all of the properties which are required of an object. Some property combinations are irreconcilable, such as for example, high strength, rigidity or hardness on the one hand and good vibration-damping, high elasticity and non-skid properties on the other hand. If a component is to combine these properties, composites of a plurality of materials are used.
In principle, it might be thought that composites having the above combined properties could be prepared from metal and rubber. However, this combination of materials has significant disadvantages:
1. Metals have a high density, i.e., the components produced from them are heavy. PA1 2. Without a coupling agent, a primer or an adhesive it is not possible to bond metal and rubber. PA1 3. It is very costly to prepare complex components such as, for example, three-dimensional structures from metal. PA1 a) the molded material A is composed of a matrix of polyamide (PA) or of a polyamide-containing (PA-containing) molding composition and of a continuous, fibrous reinforcement embedded therein, and PA1 b) the molded material B is the rubber obtained after peroxidic vulcanization of a rubber composition which has been applied to A, the rubber composition containing the following components:
Continuous-fiber-reinforced thermoplastics are, for example, described in R. F. McMahon "Developments in Reinforced Plastics-4", Elsevier Applied Science Publishers, 1984, and also in G. Brandt and H. Richter, Kunststoffe 77 (1987), P. 40. The systems described in these articles would satisfy the above-mentioned strength, rigidity and hardness requirements; however, examination shows that the reinforced plastics which have been described do not form a firm bond with rubber. The vulcanized rubber can be peeled from the interface with the thermoplastic by a small force, i.e., of less than 0.7 N/mm, in the case of a carbon fiber/polyether ether ketone/E-SBR rubber composite. Such a low level of adhesion is quite unsatisfactory for industrial purposes.
DE-A-3,615,965 discloses the preparation of a firm bond between continuous-fiber-reinforced polyphenylene ether molding compositions and certain rubbers containing double bonds, such as, for example, styrene-butadiene rubber. The adhesions achieved by this method are considerable, but the solvent resistance and also the weathering resistance of the polyphenylene ether molding compositions which are used are unsatisfactory. Hence, the conventional methods cannot therefore provide a simple preparation of components which is composed on the one hand of continuous-fiber-reinforced thermoplastics and on the other hand of rubber, and which additionally has good solvent and weathering resistance.
Further, EP-A-0,344,427 discloses a process for the preparation of a chemical bond between molding compositions based on aliphatic polyamides on the one hand and carboxyl-containing rubbers on the other hand, as well as materials prepared by the process. However, there is no indication therein that non-metallic fibers can be used.
Thus, a need clearly continues to exist for a simple preparation of components which are composed of at least one continuous fiber reinforced thermoplastic and a rubber component, and which has, at once, excellent solvent and weathering resistance.